title: DNA intermediates of meiotic recombination in synchronous S. pombe at optimal temperature.
abstract: Crossovers formed by recombination between homologous chromosomes are important for proper homolog segregation during meiosis and for generation of genetic diversity. Optimal molecular analysis of DNA intermediates of recombination requires synchronous cultures. We previously described a mutant, pat1-as2, of the fission yeast Schizosaccharomyces pombe that undergoes synchronous meiosis at 25°C when an ATP analog is added to the culture. Here, we compare recombination intermediates in pat1-as2 at 25°C with those in the widely used pat1-114 temperature-sensitive mutant at 34°C, a temperature higher than optimal. DNA double-strand breaks at most hotspots are similarly abundant in the two conditions but, remarkably, a few hotspots are distinctly deficient at 25°C. In both conditions, Holliday junctions at DNA break hotspots form more frequently between sister chromatids than between homologs, but a novel species, perhaps arising from invasion by only one end of broken DNA, is more readily observed at 25°C. Our results confirm the validity of previous assays of recombination intermediates in S. pombe and provide new information on the mechanism of meiotic recombination.
authors.affiliation: Fred Hutchinson Cancer Research Center, Division of Basic Sciences, Seattle, WA, 98109, USA, Max F. Perutz Laboratories, University of Vienna, Dr. Bohr-Gasse 9, 1030 Vienna, Austria, Cancer Research Institute, Slovak Academy of Sciences, 83391 Bratislava, Slovak Republic Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska Dolina, 842 15 Bratislava, Slovak Republic.
authors.forename: Randy W
authors.initials: RW
authors.lastname: Hyppa
authors.forename: Kyle R
authors.initials: KR
authors.lastname: Fowler
authors.forename: Lubos
authors.initials: L
authors.lastname: Cipak
authors.forename: Juraj
authors.initials: J
authors.lastname: Gregan
authors.forename: Gerald R
authors.initials: GR
authors.lastname: Smith
mesh_terms: D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair; D045566:DNA, Cruciform / Q000378:metabolism; D004271:DNA, Fungal / Q000378:metabolism*; D008540:Meiosis / Q000235:genetics*; D009154:Mutation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D011995:Recombination, Genetic; D012568:Schizosaccharomyces / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics; D013696:Temperature
chemical_list: D045566:DNA, Cruciform; D004271:DNA, Fungal; D029702:Schizosaccharomyces pombe Proteins; C087019:ran1 protein, S pombe; D017346:Protein Serine-Threonine Kinases